Drop-hammer.



No. 882,588. PATBNTED MAR. 24, .1908.

W. T. SEARS. DROP HAMMER.

APPLICATION FILED DEC. 11, 1907.

2 SHEBTS SHEBT l yenoor ttorney sses:

PATENTEDMAR. 24, 1908. W. T. SEARS.

DROP HAMMER.

APPLICATION FILED DEC. 11, 1907. 2 H SHE 2- S. j/ L Attorney UNITED STATES i l i 0 PATENT OFFICE.

WILLARD T. SEARS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO NILES-BEMENT-PON D COMPANY, OF JERSEY CITY, NEW JERSEY.

DROP-HAMIMER.

Specification of Letters Patent.

Patented March 24, 1908.

Application filed December 11, 1907. Serial No. 406,005.

the hammer, the pinching and releasing action of the rolls upon the stem being under the control of a treadle. The stem attached to the hammer may be a rod, strap, or board, preferably the latter.

The improvements will be readily understood from the following description taken in connection with the accompanying draw- I ings in which Figure 1 is a front elevation of a drop hammer exemplifying my improvements: Fig. 2 a side elevation of the same: Fig. 3 a vertical section in the plane of line b of Figs. 1 and 4: Fig. 4 a horizontal section in the lane of line a of Figs. 1 and 3 Fig. 5 a rear e evation of the valvechest, with the cover removed: and Fig. 6 a front elevation of the u per end of the treadle-rodcontrolling the vsilve.

Various scales of dimensions are employed in the several figures.

In the drawings:-l, indicates the anvil: 2, the uprights: 3, the top housings: 4, the hammer guided vertically by the uprights: 5, the stem, illustrated asa board having its lower end secured to the hammer: 6, one of the pinching rolls j ournaled in the top housing and occu ying a fixed position therein: 7, the second pinching roll: 8, a pulley for giving motion to the rolls: 9, the trigger pivoted to one of the uprights and adapted to engage under a projection of the hammer and support the hammer in elevated position at a height according to the adjustment of the trigger: 10, the rod for controlling the opening and closing of the rolls: 11, the treadle: 12, the spring for holding the treadle in up or position: 13, the rod connecting the tread e with the trigger so that depressing the treadle releases the trigger: 14, a leverpivoted to the foot of one of the uprights and having its inner end under and supporting the controlling rod 10, the outer end of this lever being heavier than the inner end: 15, a

link connecting the treadle and the outer end of lever 14, this link being of a character not capable of transmitting strain compressively, a strap form of link being illustrated: 16, a tappet rigidly secured to but adjustable on controlling rod 10 and adapted to be engaged by a lifting lug on the hammer: and 17, a spring cooperating with trigger-rod 13 and trigger 9 to permit the trigger to have releasing movement independent of treadle movement.

All of the parts thus far described are substantially as usual in this general class of drop-{hammers and are subject to the usual mo cation in the construction and arrangement of those parts.

Continuing with the drawings :18, indicates a bellcrank lever pivoted in the top housing, its vertical short arm being bifurcated and carrying the bearings of pinching roll 7, its horizontal arm be' (r mortised for the free passage of the boar forming the stem of the hammer: 19, a fluid-pressure cylinder supported by the top housing under the outer end of the bellcrank lever: 20, the piston of this cylinder: 21, the piston-rod, linked to the outer end of the bell-crank lever: 22, the valvechest of the cylinder: 23, the fluid inlet to the valvechest the fluid being, preferably, compressed air and hereinafter referred to as air: 24, a valve disposed in the valvechest, this valve being of ordinary D-type and cooperating with an exhaust port and with ports communicating with each end, respectively, of the cylinder: 25, the exhaust outlet: 26, a roller on the outer end of the valve-stem, this roller bearing against the side of controlling rod 10: 27, a spring engaging the valve-stem and urging it toward the controlling rod: and 28, a cam formed on the side of controlling rod 10 where it engages the roller 26, the cam being of such form that one vertical position of the treme position, while another vertical position of the controlling rod permits the spring to move the valve to its other extreme position.

In Fig. 3 the piston is in upper position and the rolls are so separated as to be free of the hammer stem. If air be exhausted from be low the piston and be admitted under pressure above the piston then the piston will move down and cause the rolls to pinch the e rrrrpmcontrolling rod forcesv the valve to one exhammer-stem, the rotation of the rolls causing the hammer to be lifted.

In Fig. 4.- the valve is in one extreme position, as forced there by the camon controlling rod 10, and the spring is under compression. The left-hand port, which is the one leading to the lower end of the cylinder, is in communication with the valvechest so as to admit air underthe piston, while the right hand port, which is the one leading to the top of the cylinder, is in communication with the exhaust. Such is the condition when the hammer-stem is free ot the pinching rolls and when the controlling rod is in its upper posiii on, and such is the condition of parts in In Fig. 1 the hammer is in upper position and held there by the trigger 9. The trigger may have its pivot located at high or low points to bring about selections for the position for the hammer, corresponding to ad justments being made at the connection between the trigger and the trigger rod 13, and between the tappet and the controlling rod 10. In Fig. 1 the trigger-held hammer supports controlling rod 10 in up er position. It, now, the treadle be depresse the trigger will release from the hammer and the hammer will fall and deliver its blow, the depression of the treadle straightening link 15 and maintaining the support of the controlling rod. The hammer remains down so long as the treadle remains depressed. If, now, thetreadle be allowed to rise then controlling rod 10 will descend by its own weight and bring a shallow part of its cam 28 to the valve stem roller, thus permitting spring 27 to move the j valve to osition to admit air over the piston and to 6131311817 the air from below the piston. The iston' now descends and the rolls pinch the ammer-stem and the hammer is elevated. The release of the treadle causes the trigger to go to engaging position but the yielding of spring 17 permits the hammer to displace the trigger which prom tly returns to position for engagement with t e hammer. The lifting lug on the hammer strikes the ta pet and hits controlling rod 10 and, in an obvious manner, brings about the separation of the rolls thus freeing the hammer-stem from their influence. The hammer, thus otherwise free to fall, is arrested by the trigger and upheld thereby till the treadle is again depressed. The hammer is th'us allowedv to fall at each depression of the treadle and is lifted at each release of the treadle.

I claim:

1. A drop hammer comprising an anvil, vertical guides, a hammer fitted to work in the guides a stem projecting upward from the hammer, a pair of pinching rolls adapted for rotation in contact with the stem and adapted for relative movement to and from each other so as to be in or out of contact with the stem, a fluid-pressure cylinder, a

piston therein, a connection between said piston and one of said pinch rolls to cause the movement of the piston to bring-about the opening and closing of the rolls upon the stem, a valve for controlling the flow of fluid to and from the cylinder, a treadle, and connections between the treadle and valve for controlling the movements of the valve, combined substantially as set forth.

2. A drop hammer comprising an anvil, vertical guides, a hammer fitted to work in the guides, a stem projecting upward from the hammer, a pair of pinching rolls adapted for rotation in contact with the stem and adapted for relative movement to and from each other so as to be in or out of contact with the stem, a fluid-pressure cylinder, a piston therein, a connection between said piston and one of said pinching rolls to cause the movement of the piston to bring about the opening and closing of the rolls upon the stem, a valve for controlling the flow of fluid to and from the cylinder, a treadle, connections between the treadle and valve for controlling the movements of the valve, and tappet mechanism connected with the hammer and valve to cause the hammer to act on the valve at the upper end of its stroke, combined substantially as set forth.

3. A drop hammer comprising an anvil, vertical guides, a hammer fitted to work in the guides, a stem projecting upward from the hammer, a pair of pinching rolls adapted for rotation in contact with the stem and adapted for relative movement to and from each other so as to be in or out of contact with the stem, a fluid-pressure cylinder, a piston therein, a connection between said piston and one of said pinching rolls to cause the movement of the piston to bring about the opening and closing of the rolls upon the stem, a valve for controlling the flow of fluid to and from the cylinder, a treadle, a controlling rod extending vertically and having connection with the treadle, and a cam carried by the controlling rod and cooperating with the stem of the valve in such manner that the vertical movements of the controlling rod bring about the shifting of the valve, combined substantially as set forth.

4. A drop hammer comprising an anvil, vertical guides, a hammer fitted to work in the guides, a stem projecting upward from the hammer, a pair of pinching rolls adapted for rotation in contact with the stem and adapted for relative movement to and from each other so as to be in or out of contact with the stem, a fluid-pressure cylinder, a piston therein, a connection between said piston and one of said pinching rolls to cause the movement of the piston to bring about the opening and closing of the rolls upon the stem, a valve for controlling the flow of fluid to and from the cylinder, a treadle, a controlling rod extending vertically and having 1 bring about the shifting of the valve, and

tappet mechanism connected with the hammer and GODtlOlllllg rod to cause the hammer to lift the controlling rod and shift the valve at the upper end of the hammer stroke, combined substantially as set forth.

WILLARD T. SEARS. Vitnesses:

E. H. WRAY. SAMUEL C. KAY. 

